01 Oct 2008, 10:07
Generic-user-small

Dave Vernon (1 post)

Hi,

I am using a Scriptaculous slider to scroll a div but I want to be able to control the position of the scroller using buttons too. See my example here:

http://www.stickycreation.co.uk/laurus/scroll_testX.html

Here’s the code from that page:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
        "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html>
<head>
<meta http-equiv="Content-type" content="text/html; charset=utf-8" />
<title>Use a Slider as a Scrollbar Demo</title>
		<script src="prototype.js" type="text/javascript"></script>
		<script src="slider.js" type="text/javascript"></script>
	<style type="text/css" media="screen" >
			
			/* scrollable div area */
			#scrollable1 {
				float: left;
				width: 300px;
				height: 200px;
				border: 1px solid #ccc;
				overflow: hidden;
				white-space: nowrap;
			}
			
			/* vertical track */
			#track1 {
				float: left;
				width: 15px;
				height: 200px;
				margin-left: 10px;
				background-color: #ccc;
			}
			
			/* vertical track handle */
			#handle1 {
				width: 15px;
				height: 20px;
				background-color: #f00;
				cursor: move;
			}
			
			/* horizontal track */
			#track2 {
				float: left;
				clear: both;
				width: 300px;
				height: 15px;
				margin-top: 10px;
				background-color:#ccc;
			}
			
			/* horizontal track handle */
			#handle2 {
				width: 20px;
				height: 15px;
				background-color: #f00;
				cursor: move;
			}
			
			/* scrollable div area */
			#scrollable2 {
				float: left;
				width: 284px;
				height: 184px;
				padding: 8px;
				border-top: 1px solid #ccc;
				border-left: 1px solid #ccc;
				overflow: hidden;
				white-space: nowrap;
			}
			
			/* wrap to make sure that image area is clickable */
			#wrap3 {
				float: left;
				width: 15px;
				height: 201px;
				background: transparent url(images/scrollbar-track-bottom.png) no-repeat bottom left;
			}
			
			/* top image of track */
			#track3-top {
				position: absolute;
				width: 15px;
				height: 15px;
				background: transparent url(images/scrollbar-track-top.png) no-repeat top left;
			}
			
			/* vertical track */
			#track3 {
				position: absolute;
				width: 15px;
				height: 201px;
			}
			
			/* vertical track handle */
			#handle3 {
				width: 15px;
				height: 37px;
			}
			
			/* wrap to make sure that image area is clickable */
			#wrap4 {
				float: left;
				clear: both;
				width: 301px;
				height: 15px;
				background: transparent url(images/scrollbar-track-right.png) no-repeat top right;
			}
			
			/* left image of track */
			#track4-left {
				position: absolute;
				width: 15px;
				height: 15px;
				background: transparent url(images/scrollbar-track-left.png) no-repeat top left;
			}
			
			/* horizontal track */
			#track4 {
				position: absolute;
				width: 301px;
				height: 15px;
			}
			
			/* horizontal track handle */
			#handle4 {
				width: 37px;
				height: 15px;
			}

		</style>

</head>
	<body>
		<h1>Using a Slider as a Scrollbar</h1>
		
		<h2>Using Standard Slider Controls</h2>
		<div id="scrollable1">
			This is an example of using a slider as a vertical and horizontal scrollbar.

			<ol>
				<li>Line item</li>

				<li>Line item</li>
				<li>Line item</li>
				<li>Line item</li>
				<li>Line item</li>
				<li>Line item</li>
				<li>Line item</li>

			</ol>
			
			This is a demo using a slider as a vertical and horizontal scrollbar.
			
			<ul>
				<li>Line item</li>
				<li>Line item</li>
				<li>Line item</li>
				<li>Line item</li>

				<li>Line item</li>
				<li>Line item</li>
				<li>Line item</li>
			</ul>
			
			This is an example of using a slider as a vertical and horizontal scrollbar.
		</div>

		<div id="track1"><div id="handle1"></div></div>

		<div id="track2"><div id="handle2"></div></div>
		
		
		
		<h2><br style="clear: both;" /></h2>
        
        <a href="#">scroll left</a>  |  <a href="#">scroll right</a>
    <script type="text/javascript" language="javascript">
		// <![CDATA[
		
			// vertical slider control
			var slider1 = new Control.Slider('handle1', 'track1', {
				axis: 'vertical',
				onSlide: function(v) { scrollVertical(v, $('scrollable1'), slider1);  },
				onChange: function(v) { scrollVertical(v, $('scrollable1'), slider1); }
			});
			
			// horizontal slider control
			var slider2 = new Control.Slider('handle2', 'track2', {
				onSlide: function(v) { scrollHorizontal(v, $('scrollable1'), slider2);  },
				onChange: function(v) { scrollHorizontal(v, $('scrollable1'), slider2); }
			});
			
			// vertical slider control
			var slider3 = new Control.Slider('handle3', 'track3', {
				axis: 'vertical',
				onSlide: function(v) { scrollVertical(v, $('scrollable2'), slider3);  },
				onChange: function(v) { scrollVertical(v, $('scrollable2'), slider3); }
			});
			
			// horizontal slider control
			var slider4 = new Control.Slider('handle4', 'track4', {
				onSlide: function(v) { scrollHorizontal(v, $('scrollable2'), slider4);  },
				onChange: function(v) { scrollHorizontal(v, $('scrollable2'), slider4); }
			});
			
			// scroll the element vertically based on its width and the slider maximum value
			function scrollVertical(value, element, slider) {
				element.scrollTop = Math.round(value/slider.maximum*(element.scrollHeight-element.offsetHeight));
			}
			
			// scroll the element horizontally based on its width and the slider maximum value
			function scrollHorizontal(value, element, slider) {
				element.scrollLeft = Math.round(value/slider.maximum*(element.scrollWidth-element.offsetWidth));
			}
			
			// disable vertical scrolling if text doesn't overflow the div
			if ($('scrollable1').scrollHeight <= $('scrollable1').offsetHeight) {
				slider1.setDisabled();
				$('track1').hide();
			}
			
			// disable horizontal scrolling if text doesn't overflow the div
			if ($('scrollable1').scrollWidth <= $('scrollable1').offsetWidth) {
				slider2.setDisabled();
				$('track2').hide();
			}
			
			// disable vertical scrolling if text doesn't overflow the div
			if ($('scrollable2').scrollHeight <= $('scrollable2').offsetHeight) {
				slider3.setDisabled();
				$('wrap3').hide();
			}
			
			// disable horizontal scrolling if text doesn't overflow the div
			if ($('scrollable2').scrollWidth <= $('scrollable2').offsetWidth) {
				slider4.setDisabled();
				$('wrap4').hide();
			}

		// ]]>
		  </script>
		  
	</body>
</html>

This file links to the prototype framework and the js file slider.js, which contains the following code:

// script.aculo.us slider.js v1.6.5, Wed Nov 08 14:17:49 CET 2006

// Copyright (c) 2005, 2006 Marty Haught, Thomas Fuchs 
//
// script.aculo.us is freely distributable under the terms of an MIT-style license.
// For details, see the script.aculo.us web site: http://script.aculo.us/

if(!Control) var Control = {};
Control.Slider = Class.create();

// options:
//  axis: 'vertical', or 'horizontal' (default)
//
// callbacks:
//  onChange(value)
//  onSlide(value)
Control.Slider.prototype = {
  initialize: function(handle, track, options) {
    var slider = this;
    
    if(handle instanceof Array) {
      this.handles = handle.collect( function(e) { return $(e) });
    } else {
      this.handles = [$(handle)];
    }
    
    this.track   = $(track);
    this.options = options || {};

    this.axis      = this.options.axis || 'horizontal';
    this.increment = this.options.increment || 1;
    this.step      = parseInt(this.options.step || '1');
    this.range     = this.options.range || $R(0,1);
    
    this.value     = 0; // assure backwards compat
    this.values    = this.handles.map( function() { return 0 });
    this.spans     = this.options.spans ? this.options.spans.map(function(s){ return $(s) }) : false;
    this.options.startSpan = $(this.options.startSpan || null);
    this.options.endSpan   = $(this.options.endSpan || null);

    this.restricted = this.options.restricted || false;

    this.maximum   = this.options.maximum || this.range.end;
    this.minimum   = this.options.minimum || this.range.start;

    // Will be used to align the handle onto the track, if necessary
    this.alignX = parseInt(this.options.alignX || '0');
    this.alignY = parseInt(this.options.alignY || '0');
    
    this.trackLength = this.maximumOffset() - this.minimumOffset();

    this.handleLength = this.isVertical() ? 
      (this.handles[0].offsetHeight != 0 ? 
        this.handles[0].offsetHeight : this.handles[0].style.height.replace(/px$/,"")) : 
      (this.handles[0].offsetWidth != 0 ? this.handles[0].offsetWidth : 
        this.handles[0].style.width.replace(/px$/,""));

    this.active   = false;
    this.dragging = false;
    this.disabled = false;

    if(this.options.disabled) this.setDisabled();

    // Allowed values array
    this.allowedValues = this.options.values ? this.options.values.sortBy(Prototype.K) : false;
    if(this.allowedValues) {
      this.minimum = this.allowedValues.min();
      this.maximum = this.allowedValues.max();
    }

    this.eventMouseDown = this.startDrag.bindAsEventListener(this);
    this.eventMouseUp   = this.endDrag.bindAsEventListener(this);
    this.eventMouseMove = this.update.bindAsEventListener(this);

    // Initialize handles in reverse (make sure first handle is active)
    this.handles.each( function(h,i) {
      i = slider.handles.length-1-i;
      slider.setValue(parseFloat(
        (slider.options.sliderValue instanceof Array ? 
          slider.options.sliderValue[i] : slider.options.sliderValue) || 
         slider.range.start), i);
      Element.makePositioned(h); // fix IE
      Event.observe(h, "mousedown", slider.eventMouseDown);
    });
    
    Event.observe(this.track, "mousedown", this.eventMouseDown);
    Event.observe(document, "mouseup", this.eventMouseUp);
    Event.observe(document, "mousemove", this.eventMouseMove);
    
    this.initialized = true;
  },
  dispose: function() {
    var slider = this;    
    Event.stopObserving(this.track, "mousedown", this.eventMouseDown);
    Event.stopObserving(document, "mouseup", this.eventMouseUp);
    Event.stopObserving(document, "mousemove", this.eventMouseMove);
    this.handles.each( function(h) {
      Event.stopObserving(h, "mousedown", slider.eventMouseDown);
    });
  },
  setDisabled: function(){
    this.disabled = true;
  },
  setEnabled: function(){
    this.disabled = false;
  },  
  getNearestValue: function(value){
    if(this.allowedValues){
      if(value >= this.allowedValues.max()) return(this.allowedValues.max());
      if(value <= this.allowedValues.min()) return(this.allowedValues.min());
      
      var offset = Math.abs(this.allowedValues[0] - value);
      var newValue = this.allowedValues[0];
      this.allowedValues.each( function(v) {
        var currentOffset = Math.abs(v - value);
        if(currentOffset <= offset){
          newValue = v;
          offset = currentOffset;
        } 
      });
      return newValue;
    }
    if(value > this.range.end) return this.range.end;
    if(value < this.range.start) return this.range.start;
    return value;
  },
  setValue: function(sliderValue, handleIdx){
    if(!this.active) {
      this.activeHandleIdx = handleIdx || 0;
      this.activeHandle    = this.handles[this.activeHandleIdx];
      this.updateStyles();
    }
    handleIdx = handleIdx || this.activeHandleIdx || 0;
    if(this.initialized && this.restricted) {
      if((handleIdx>0) && (sliderValue<this.values[handleIdx-1]))
        sliderValue = this.values[handleIdx-1];
      if((handleIdx < (this.handles.length-1)) && (sliderValue>this.values[handleIdx+1]))
        sliderValue = this.values[handleIdx+1];
    }
    sliderValue = this.getNearestValue(sliderValue);
    this.values[handleIdx] = sliderValue;
    this.value = this.values[0]; // assure backwards compat
    
    this.handles[handleIdx].style[this.isVertical() ? 'top' : 'left'] = 
      this.translateToPx(sliderValue);
    
    this.drawSpans();
    if(!this.dragging || !this.event) this.updateFinished();
  },
  setValueBy: function(delta, handleIdx) {
    this.setValue(this.values[handleIdx || this.activeHandleIdx || 0] + delta, 
      handleIdx || this.activeHandleIdx || 0);
  },
  translateToPx: function(value) {
    return Math.round(
      ((this.trackLength-this.handleLength)/(this.range.end-this.range.start)) * 
      (value - this.range.start)) + "px";
  },
  translateToValue: function(offset) {
    return ((offset/(this.trackLength-this.handleLength) * 
      (this.range.end-this.range.start)) + this.range.start);
  },
  getRange: function(range) {
    var v = this.values.sortBy(Prototype.K); 
    range = range || 0;
    return $R(v[range],v[range+1]);
  },
  minimumOffset: function(){
    return(this.isVertical() ? this.alignY : this.alignX);
  },
  maximumOffset: function(){
    return(this.isVertical() ? 
      (this.track.offsetHeight != 0 ? this.track.offsetHeight :
        this.track.style.height.replace(/px$/,"")) - this.alignY : 
      (this.track.offsetWidth != 0 ? this.track.offsetWidth : 
        this.track.style.width.replace(/px$/,"")) - this.alignY);
  },  
  isVertical:  function(){
    return (this.axis == 'vertical');
  },
  drawSpans: function() {
    var slider = this;
    if(this.spans)
      $R(0, this.spans.length-1).each(function(r) { slider.setSpan(slider.spans[r], slider.getRange(r)) });
    if(this.options.startSpan)
      this.setSpan(this.options.startSpan,
        $R(0, this.values.length>1 ? this.getRange(0).min() : this.value ));
    if(this.options.endSpan)
      this.setSpan(this.options.endSpan, 
        $R(this.values.length>1 ? this.getRange(this.spans.length-1).max() : this.value, this.maximum));
  },
  setSpan: function(span, range) {
    if(this.isVertical()) {
      span.style.top = this.translateToPx(range.start);
      span.style.height = this.translateToPx(range.end - range.start + this.range.start);
    } else {
      span.style.left = this.translateToPx(range.start);
      span.style.width = this.translateToPx(range.end - range.start + this.range.start);
    }
  },
  updateStyles: function() {
    this.handles.each( function(h){ Element.removeClassName(h, 'selected') });
    Element.addClassName(this.activeHandle, 'selected');
  },
  startDrag: function(event) {
    if(Event.isLeftClick(event)) {
      if(!this.disabled){
        this.active = true;
        
        var handle = Event.element(event);
        var pointer  = [Event.pointerX(event), Event.pointerY(event)];
        var track = handle;
        if(track==this.track) {
          var offsets  = Position.cumulativeOffset(this.track); 
          this.event = event;
          this.setValue(this.translateToValue( 
           (this.isVertical() ? pointer[1]-offsets[1] : pointer[0]-offsets[0])-(this.handleLength/2)
          ));
          var offsets  = Position.cumulativeOffset(this.activeHandle);
          this.offsetX = (pointer[0] - offsets[0]);
          this.offsetY = (pointer[1] - offsets[1]);
        } else {
          // find the handle (prevents issues with Safari)
          while((this.handles.indexOf(handle) == -1) && handle.parentNode) 
            handle = handle.parentNode;
            
          if(this.handles.indexOf(handle)!=-1) {
            this.activeHandle    = handle;
            this.activeHandleIdx = this.handles.indexOf(this.activeHandle);
            this.updateStyles();
            
            var offsets  = Position.cumulativeOffset(this.activeHandle);
            this.offsetX = (pointer[0] - offsets[0]);
            this.offsetY = (pointer[1] - offsets[1]);
          }
        }
      }
      Event.stop(event);
    }
  },
  update: function(event) {
   if(this.active) {
      if(!this.dragging) this.dragging = true;
      this.draw(event);
      // fix AppleWebKit rendering
      if(navigator.appVersion.indexOf('AppleWebKit')>0) window.scrollBy(0,0);
      Event.stop(event);
   }
  },
  draw: function(event) {
    var pointer = [Event.pointerX(event), Event.pointerY(event)];
    var offsets = Position.cumulativeOffset(this.track);
    pointer[0] -= this.offsetX + offsets[0];
    pointer[1] -= this.offsetY + offsets[1];
    this.event = event;
    this.setValue(this.translateToValue( this.isVertical() ? pointer[1] : pointer[0] ));
    if(this.initialized && this.options.onSlide)
      this.options.onSlide(this.values.length>1 ? this.values : this.value, this);
  },
  endDrag: function(event) {
    if(this.active && this.dragging) {
      this.finishDrag(event, true);
      Event.stop(event);
    }
    this.active = false;
    this.dragging = false;
  },  
  finishDrag: function(event, success) {
    this.active = false;
    this.dragging = false;
    this.updateFinished();
  },
  updateFinished: function() {
    if(this.initialized && this.options.onChange) 
      this.options.onChange(this.values.length>1 ? this.values : this.value, this);
    this.event = null;
  }
}

My question is how can I enable the text-link buttons I have created (scroll left/scroll right) to move the scroll bar together with the div content along? If it’s not possible with the code I’ve used is there a better solution I could use? Any help would be greatly appreciated!

Dave Vernon

25 Nov 2008, 15:27
Me_fb_pragsmall

Tony Amoyal (1 post)

Have you made any progress on this issue? I am working on the same thing right now. If you have a solution, it would be great if you could post it. If not, we could work together using this discussion to post progress.

Thanks,

Tony

14 Feb 2009, 17:40
Avatar_mw_large_pragsmall

Christophe Porteneuve (63 posts)

Hey guys, sorry I didn’t reply earlier.

@Slider@ allows programmatic positioning through its @setValue@ method, which takes the value for the handle, and optionally the handle index (starting from zero), if there are multiple handles.

So based on the code here, and considering the @slider2@ variable is the horizontal slider, all we need to do is:

a) Add proper classes to the left/right links, like so:

<a class="scroll left" href="#">scroll left</a>  |  <a class="scroll right" href="#">scroll right</a>

b) Follow @slider2@’s creation with code such as the following:

document.observe('click', function(e) {
  var activator = e.findElement('a.scroll');
  if (!activator) return;
  e.stop();
  var sign    = activator.hasClassName('left') ? -1 : 1;
  var offset  = sign * ((slider2.maximum - slider2.minimum) / 10);
  slider2.setValue(slider2.value + offset);
});

This requests sliding of 10%, left or right. @Slider@’s internal controls will prevent overshooting.

‘HTH

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